Rule Definition
In PHP source code if there is a write action to a property that does not exist and there is no '__set'-method, the property will be created. The '__get' method will only be called if there is no property with the given name. So having properties without a __set method could produce unexpected values for the __get method of the same property.

Remediation
Modify the source code and add the '__set' method with an appropriate default. Also consider throwing an Exception that returns false.

Violation Code Sample

<?php
      $rec = new Rectangle(5, 5);
      echo $rec->area; //outputs 25

    ?>

Fixed Code Sample

<?php
      $rec->area = 10;
      echo $rec->area; //outputs 10
    ?>